loading/importing a (gimp) pattern into blender

I have this problem. I created a pattern in GIMP and I want to put this on an object I created. For example: I create a wood pattern in gimp and now I import or load this into Blender and put this pattern on let’s say a cube.

Now raise the following questions:

what difference is there betweent loading a background or import a raw photo?
Can I deform and use these patterns in any way I want?

What is the best way to do it?

For example: I create a wood pattern in gimp and now I import or load this into Blender and put this pattern on let’s say a cube.
Depending on your goals, you would probably need to make a UV map before making your pattern (texture). Or you might be able to use a decal. You’ll want to read the manual sections on UV mapping and Texture Map Input (for decals) and see which one is most relevant for you.

what difference is there betweent loading a background or import a raw photo?
A background is usually used as a modelling reference (which could be a photo/blueprint/whatever). I don’t really know what you mean by import a raw photo. Do you want to use this photo as a modelling aid or add it to your model as a texture?

Can I deform and use these patterns in any way I want?
Again, depends on what you mean. You can use and alter textures in a number of ways e.g. to provide colour, bump mapping, displacement, transparency etc, but they all have to be set up in a particular way. Check the Materials and Texturing sections in the manuals for an overview. If have a specific effect in mind, let us know and we can provide more specific feedback.